Akron, Ohio duo the Black Keys delivered an hour-long set of bluesy rockers that were every bit as grizzled as frontman Dan Auerbach’s increasingly bushy beard. A rowdy “Set You Free” found drummer Patrick Carney pummeling his kit like a back-alley brawler finishing off an over-matched opponent; “Strange Times” veered between spacey psychedelia and whale calls of feedback; a cover of Captain Beefheart’s “I’m Glad” — all chiming guitar and heartfelt vocals — proved a lone tender moment. Still, Auerbach seemed struck by the crowd’s mellow nature. “We should go for a record today,” he offered near the set’s midpoint. “World’s Most Peaceful Mosh Pit. Can we do it?”